Voice over IP (“VoIP”) is a relatively recent development that is utilized to transmit voice conversations over a data network using the Internet Protocol (“IP”). Internet Protocol is a part of the TCP/IP family of protocols described in software that tracks the Internet address of nodes, routes outgoing messages, and recognizes incoming messages. Such a data network may be the Internet or a corporate intranet, or any TCP/IP network. There are several potential benefits for moving voice over a data network using IP. First, there is a savings in money compared to the need to use traditional tolled telecommunications networks. Additionally, Voice over IP enables the management of voice and data over a single network. And, with the use of IP phones, moves, adds and changes are easier and less expensive to implement. Moreover, additional and integrated new services, including integrated messaging, bandwidth on demand, voice e-mails, the development of “voice portals” on the Web, simplified setting up and tearing down, and transferring of phone calls are capable.
Using Voice over IP technology, phone systems can communicate with each other over existing TCP/IP data networks typically present between remote offices. This feature alone can eliminate the need for expensive, dedicated circuits between facilities. The shared bandwidth can also be used for voice calls and data communication simultaneously; no bandwidth is dedicated to one or the other.
Another advantage of a Voice over IP system is the ability to implement a phone system over an existing data network that is already connecting workstations within a local area network, such as over an Ethernet. An Ethernet operates over twisted wire and over coaxial cable for connecting computers, printers, workstations, terminals, servers, etc., within the same building or a campus. The Ethernet utilizes frame packets for transmitting information. Voice over IP can utilize such packet switching capabilities to connect IP phones onto the Ethernet.
Traditional voice mail systems within a wide area network possess limitations that reduce their effectiveness. For example, such telephone systems typically need to have either a centralized voice mail system that has to be accessed remotely, or separate and distinct voice mail systems within each location with only a limited ability to share information. What is desired is a telephone system having voice mail functionality that is essentially transparent to the location of the user.